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(No Model.) 2 Sheets-Sheet 1.

M. W. SEWALL. METHOD OF CONTROLLING SHUT-OFF AND THROTTLE VALVES.

No. 430,089. Patented June 10, 1890.

ATTORNEY.

1 ms 20.. mom-mum, wAsNmmoN, a. c.

2 Sheets-Sheet 2;

(No-Model.)

M. W. SEWALL. METHOD OF CONTROLLING SHUT-OPP AND THROTTLE VALVES.

Patented June 10 Elm-430.089.

' VENTOR.

ATTORNEK UNITED STATES MINOTT XV. SEXVALL, OF NEW YORK, N. Y.

METHOD OF CONTROLLING SHUT-OFF AND THROTTLE VALVES.

' SPECIFICATION forming part of Letters Patent No. 430,089, dated June 10, 1890.

Application filed December 11, 1888.

To all 1077,0722, it may concern.-

Be it known that I, MINoTr W. SEWALL, a citizen of the United States, residing at the city, county, and State of New York, have invented certain new and useful Improvements in Methods of Controlling Shut-Off and Throttle Valves, of which the following is a specification.

This invention relates to piston-valves, annular valves, disk-valves, or other forms employed to shut off or to throttle the flow of fluid subject thereto, and actuated for said purpose by the application of a pressure or of opposing pressures applied to a part of said valves exposed in an independent chamber or chambers.

The invention is especially applicable to stop-valves employed to admit or retard to a certain degree the delivery of firing-fluid from the reservoirs to the gun-barrel of a pneumatic gun, said valves remaining open at a fixed point during the gun action, while the intermission of discharge is controlled by the usual separate firing-valve employed in conjunction therewith. V

The object of the invention is to obtain a positive control over the valve-movements, and to facilitate the handling of valves, especially of large size, controlling a high degree of pressure or a large volume of fluid; and said invention consists in a method of actuating and retaining such valves when employed to oontrolagaseous fluid, by means of pressure applied to their opposite actuating-pressure areas, exposed exclusively to the actuating-fluid in chambers adapted there-' for, and in employing a liquid-applying medium in conjunction with said actuatingfiuid, and in controlling the admission or discharge thereof through suitable intercepting valves or cocks adapted for looking or confining the liquid as against the throttling or shut-off valve movements to arrest and retain the latter at any point of stroke.

The invention may be carried into practice by any of the various forms of valves herein shown. In its use as a throttlingvalve in conjunction with an automatic discharge-valve as the firing-valve of a pneumatic gun the herein-described throttling adjustment is employedto determine the discharge-valve-delivery capacity, thereby ex- Serial No. 293,297. (No man.)

tending the range of adjustment applied to the latter.

In order to enable others to understand and use my said invention, I will proceed to describe the details of construction of certain forms of valves herein instanced as adapted to carry the invention into practice, explain their operation, and to subsequently po nt out in the appended claims the method WlllGll I claim-as new.

Referring to the accompanying drawings, Figure 1 is a sectional elevation illustrating the invention as applied to a piston throttlevalve; Fig. 2, a sectional elevation illustrating the invention as applied to an annular valve; and Fig. 3, a sectional elevation illustrating also the annular valve, but embodying the feature aforesaid of providlng a straightway fluid passage through the casing.

Similar letters of reference indicate parts having corresponding functions throughout the views.

A, Fig. 1, is atriple piston automatic valve wherein the interior or central piston Fcomposes the valve proper, and the exterior ones G H are employedto balance and also to actuate the said interior piston-valve.

B is theinlet and O the outlet port, the functions whereof are, however, capable of reversal.

. D E are the actuating-chambers, wherein the hydraulic motive power is applied to actuate the valve A in either direction, said chambers having pipe-connections a and cooks b, as three-way cocks adapted to alternately charge or discharge through said pipe-connections by pressure-pipes c and exhaustpipes d.

The actuating pistons G H are packed,

preferably, by cup-leather packings turned in opposite directions to resist pressure from both ways, and the piston F, provided with similar packings in its circumferential seat, turned in a common direction toward the inletpressure. Otherwise, as in steam-controlling valves, expansive metallic packingrings may be employed.

P is an indicator operated over the scale 19 by the small piston-rod q, to indicate the extent of valve-opening and enable the operator to adjust the same at any desired point.

I is a deflector (open at f) adapted to direct the currentof the subject-fluid and lessen its friction as far as practicable.

In Figs. 2 and 3 the annular valves A are projected or retracted to or from their seating points, moving between the interiorly-circumferential cores .T and the eXteriorly-circumferential cylinders K by the alternate charge or discharge of oppositely applied pressures in chambers E and D, respectively. The means of applying said pressures in both instances corresponds with that described in reference to Fig. 1, as will be understood by an inspection of said Figs. 2 and 3, the passages a, which communicate to chambers D interior to the valve-annulus being adapted to extend thereto through the central stationary cores J, as through the cavity L in the instance of Fig. 3, wherein said packages are located through the webs M, as shown. The cup-packings are provided, as shown, upon all the moving surfaces at the portions which separate the several chambers.

The construction shown in Fig. 3 consists in supporting the entire valve structure (with its actuating-chambers) within and centrally to the outer casing by means of webs M, ranged radially between said casings in any desired,

number, connecting the same together, preferably, in a single casting. An annular passage for the subject fluid or a series of passages is thereby formed around the valve, permitting the currents to pass in as nearly a continuous direction as'attainable with this form of valve. The tapered heads N O of the interior casing assist to divide the currents flowing in either direction, as the case may be, when the valve is open.

In operation the pistons F H, Fig. 1, are balanced when the valve is closed by the surrounding pressure in B, and when open the pressure that takes place in chambers O C likewise balances between F and G, all the piston diameters being equal. The valve as a whole being thus interiorly balanced is capable of being moved in either an opening or a closing direction by predominant pressure in chamber D or E, respectively, the operator observing and adjusting such movements under positive control bymeans of the indicator P and valves 1) b, and locking said movements when the desired adjustment is obtained by the means aforesaid of intercepting the actuating-liquid. The valves, Figs. 2 and 3, are free from pressure of the subject-fluid (in the direction of movement) when seated, and are therefore held in said position by equal pressures in D and E, predominant on the greater area in E. \Vhen E is released, pressure in D performs the opening stroke. The pressure in E may be less in degree than the subjectfluid; but it must be sufficient upon the given excess of area to overcome the presence of the subject-fluid (upon the seating end of the valve) for the purpose of returning the valve to its closed position. It will therefore be understood that in practice I may employ a low actuating-pressure for effecting the control of a subject-fluid under high pressure.

The latter feature applies to all valves constructed and actuated under the herein-described system. 7

From the foregoing it will be understood that the liquid-pressure applied to the valve to actuate and retain it in position is entirely independent of the pressure of the subjectfluid passing through pipes 13 and G, and that such fluid-pressure in pipes B and C may or may not be taken into consideration, accordingly as it is desired to have ease of movem ent of the throttle-valve. Of course for ease of working it is better that the throttle-valve F should be balanced.

I do not herein claim the construction or combination of mechanism described, as the mechanism is claimed in an application of even date herewith, to which the Patent Office has given the serial number 293,298.

It is to be understood that I do not limit my invention to the specific forms herein cited; but I claim, broadly The method of controlling the flow of an elastic fluid in a pipe, which consists in interposing a throttle-valve in the pipe, actuating said valve by the pressure of an inelastic fluid independent of the subject-fluid in the pipe, and retaining the piston in any adjusted position by the pressure of said inelastic fluid, substantially as described.

MIN OTT XV. SEWVALL. WVitnesses:

CHAS. WV. FORBES, JOHN A. ELLIs. 

